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Found 26 results

  1. Dew strap controller (PWM) done at last (waited ages for some kit from China). 4 x 10W channels, individually fused, switched & controlled, channel switch LED brightness indicates power output. 12V 5A DC input switched & fused. Compared to the cost of a 'bought' one, I'd need to value my time at less than youth minimum wage, but you can't put a price on smug self-satisfaction :-) Circuit idea shamelessly nicked from http://www.blackwaterskies.co.uk/2013/05/a-cheap-multi-channel-dew-heater.html
  2. Hi there, I have a question regarding dew heaters and power. I have this on a SW 150PDS: https://www.astroshop.eu/heater-bands/omegon-heater-strap-secondary-mirror-heating-strip-small/p,56529 Specs: Heating power 2,2 Amperage (A) 0,18 Power supply 12 Cable length (m) 2 I have this on an orion 50mm guidescope: https://www.astroshop.eu/heater-bands/omegon-dew-heater-20cm-50mm-finderscope-/p,53511 Specs: Heating power 4 Amperage (A) 0,3 Power supply 12 Cable length (m) 1 And i have this Dewheater controller: https://www.astroshop.eu/controls/hitec-astro-4-channel-dew-controller/p,57478#tab_bar_0_select Specs: 12v 2A per channel. Truth is my thoughts have been on other equipment and AP setup since im still a newbie in AP, so I've only used the secondary-mirror heater a couple of sessions. My question is since there is adjustable power on the controller- How much do i turn the switches? Will full power affect seeing for example because of heated air? Is half a turn enough? Some general info on this?
  3. Hello, regarding my 150 Mak, i plan on storing it in my garage most of the time a least in the colder months where equilibrium will take longest, if i bring it straight outside i can see an issue with moisture but if i plan on driving somewhere should i be using a desiccant?? does it stay on the scope all the time when not using it in storage? thanks!
  4. Hi all, just a quick question: saturday night I was out observing, and towards the end of my session it got so humid, my primary mirror had dew droplets on it... (150/750 Newton) Should I be looking at buying a dew heater strip, or should I follow what others write: "if your newton primary fogs up, it's time to go home"? Thanks! Gerhard. ps. btw the dew produced some interesting haloes around bright stars! :-DD
  5. Hey guys, I need some advice on an issue I'd never encountered before. Dew. So on Saturday I was testing out my new power tank i've spent the last 3 months building and planning (post to come soon), and as it was an exceptionally clear night I thought I'd image the Andromeda galaxy for the first time. All was not well to begin with, my PHD 2 kept messing up and it looked like my mount corrections were sometimes off the scale continuously. It took me about an hour of tinkering and calibrating to realise that closing and reopening PHD was all I needed to do as after that the mount remained relatively stable. I took my first light frame (1600iso 120s) of Andromeda and my god was it incredible, I was very excited. As my histogram was not central or anywhere I was happy with I reduced the next light frame to 800iso and then upped the exposure time to 5 mins. The image came out a lot worse, so I decided to up the iso back up to 1600 but keep the remaining time. I had literally no idea what was going on as I had never experienced it before. I looked at my guidance system and it appeared to see the galaxy somewhat fainter slightly maybe but still on target so I know I hadn't drifted off to one of the neighbouring galaxies. I looked through my finder scope and all was well. No idea. So I relocated to Pleiades but this time I took my DSLR out. I shone my headlamp down the SW 200P and saw the primary was fine. But then I noticed on my Auto guider scope and my finder scope that their lenses were rather 'moist' But still my main OTA wasn't. I took my headlamp off again and looking down my main tube and shining my headlamp through the eyepiece I saw the culprit. My secondary mirror had so much dew on it, it was nowhere near clear. I assumed this was definitely the problem? But had nothing I could do about it. So the question is, I need a solution to stop this from happening. I don't want to spend a tonne of money on this as it's nowhere near payday yet! I need a solution that can sort out my ota secondary from getting too moist plus also my other equipment. I've seen other people talk about dew bands and controllers, but I need this for 3 different scopes it may get costly. I also found it weird how I started imaging last winter and never encountered dew at all until the other night! There is a star party my local Astronomy association is pulling for the public in two weeks and as my scope has been deemed reserved for observing to the public, I'd like to have a solution before then just in case my scope fogs up during that show! I have a powertank with 3 12v outputs and USB sockets which is about 3 meters from my scope at all times so I could use that to power anything I need. Any night is a good night if you learn something, whether it's a good or bad thing Any suggestions please? DIY is fine!
  6. Hi, I have moved from a Newt to a refractor (SW ED80 DS-Pro) so I have also bought a Hitech dew controller and a couple of tapes for the ota and finder/guider. I am wondering how high to set the dials? How hot can these tapes get, if wound up to full are they capable of damaging the kit? And on the ED80 where should I position the belt, should it go around the shield adjacent to the objective or further forward? Thanks, Neil.
  7. Hi, After having spent the last 2 evenings in the back garden in amazement I have realised that I need to invest in some sort of dew control equipment. I notice that there a 2 main sorts out there, those that run with controllers and those that say a controller is not required. HHEELLLPPPPPP !!!!!!!! My budget is busted but I know that if I just go for the cheapest option it will be wrong so a little advice would be gratefully appreciated. Graham
  8. Experienced the below last night - I put this down to dew on the objective (the images deteriorated steadily through the subs I took - brighter and brighter doughnuts), but nonetheless an interesting pattern that I hadn't seen before - any similar experiences? I wondered if it's the focal reducer in line that's helping to cause the "doughnut" rather than a "fuzzy star" as I'd normally expect. There's no obsttruction as this is a 'frac - if it was an SCT I would have been less surprised. (And I have dew heaters as well, I just don't tend to need them as the FLT110 has a decent dew shield, and the dome keeps a lot of the dew off - think it might be more the generally high humidity we've had here - mist and fog the last couple of mornings. Dew heaters on next time regardless...). Also it has reminded me that the camera must be due a desiccant bake with all the moisture about! (ST2000XM, Astrodon 5nm HA, FLT110 + WO FLAT4 reducer - single 20min sub)
  9. Making of a USB heating band. I needed something that was much lighter to my portable mount than what I had when I use my EQ6 mount. The powersourche are a car battery. Now I try to use a USB battery or a powerbank as a powersourche to my heating band when I use the portable mount. Just 0.3 kilogram compare to 25 kilogram! When I use my portable mount I don't have a telescope but camera lenses. There is normally very limted space where to mount a heating band on a camera lens. I needed a heating band that was much more narrower then the ones you can buy. Or have anyone found any? Anyway, I have fun when I building things! http://astrofriend.eu/astronomy/projects/project-heating-band/project-heating-band.html#part05 Or from beginning: http://astrofriend.eu/astronomy/projects/project-heating-band/project-heating-band.html Be carefull if you try to do something like this, powerbanks that I used here has much energy stored and a shortcut can easily overload it and then maybe get on fire! You must know what you are doing, I don't take any responsibilty! /Lars
  10. Hi everybody, i am in the middle of a star photo session with my canon 550d on tripod... dew built up... i cleaned the lens... 10 minutes later it's dew all over again! Any ideas ?! YANQ= yet another noob question.....
  11. Hi all. I'm hoping for some advice on a subject which I know has had a lot of air time, but which I'm still wrestling with. Firsty, I know I get dew on my secondary mirror and it has wrecked many a DSO photgraphy session. I've fitted a home made heater, and this seems to fix it. It's insulated with neoprene, and runs at a very low wattage (about 0.4W) , so hopefully not too much turbulence. Next step is to do the same to the guide scope, which also mists up after about an hour, and then maybe the primary with a very low wattage. The main puzzle for me is this: Some folk say the mirrors are huge heat reserves, and take ages to cool down, during which time they cause turbulence. But other folk say the mirrors drop in temperature rapidly and go below the dew point, and then suffer condensation. I suspect theres some truth in both statements, but this doesnt simplify how to deal with it. Probably the main consideration is that the primary is much less ikely to suffer dew than the secondary, and so they have different problems and solutions. It would be easy to say that turbulence is in the eye of the beholder, but for sure when I'm focussing - using the camera and Live View with high screen mag - there appears to be turbulence aplenty even after an hour of cooling and before putting the secondary heater on. Of course this could be atmospheric, rather than tube currents. Rather than go through all my (muddy) thinking, can I just ask some direct questions please which relate to all this. 1. Is the small amount of heat on my secondary likely to cause any significant turbulence? 2. Is the turbulence that I see on the screen likely to be caused by the OTA? 3. I havent actually seen dew on the primary - but I've read that low grade condensation can affect the reflection. Is heating of the primary maybe just unneccesary? 4. If I heat the guidescope with a belt at about 2.5W, might this adversely affect the guiding property? 5. If I use an exhaust fan to cool the primary, is there any prospect that the air current will: a. increase dew on the primary and/or secondary by drawing in more damp air? b. reduce dew on the primary and/or secondary by evaporation? I'd be really grateful for any help with this. My next step is to wire up some kind of controller, and it would be useful to know what I'm likely to need to run before doing this. Many thanks
  12. Hello everyone! Im having issues regarding dew during colder nights while imaging. I’m aware of how to solve the issue of dew forming on front elements of scopes/lenses using dew heaters, however I’m also concerned with the dew that forms on my non-weatherproof DSLR body and imaging laptop. Does anyone have any suggestions on how to combat this? Thanks!
  13. Hello! I have been looking through the forums sections of this site and found that nichrome wire is a very popular material for dew heaters. I was using my DSLR a several weeks back, and the dew was horrible and it encouraged me to build a nichrome heater. My first heater prototype consisted of 22" of wire with a resistance of 4.08 ohm per foot connected directly into a 12V power supply (consisting of 8 AA batteries in parallel). It was wrapped in duck tape. It worked for a while, but then the batteries began to overheat and I had to pull the heater out to let them cool. When I used the same prototype heater on 6V (4 AA batteries) it didn't have this same overheating issue, but it produced less heat then when it was on 12V. I'm not using a pulse width modulator, but would that solve this issue? I'm worried as the heater is only really around 8 ohm, it may be short circuiting with such little resistance. The wire can't be terribly long as this is just to heat a DSLR lens. Any input on a solution would be greatly appreciated. Thank you.
  14. Could use some advice from anyone who has made a DSLR COOL BOX. I have now completed my project, it turned out to be very effective at lowering the temperature of the camera, I managed a 25c drop. However, this caused the coma corrector that attaches the camera / cool box to the scope to significantly drop in temperature also and dew formed on it inside the focusing tube during the imaging session as a result, I image using a 130P-DS Newtonian. It took a couple of hours of cooling for this to occur mind you and as the box is sealed with desiccant inside its only the outside surface of the coma corrector / attached 2" filter that has a dew issue. Has anyone else had this issue? Would placing a 15cm eyepiece dew heater around the focusing tube convey sufficient heat into the coma corrector to prevent this? Cheers, Adam
  15. I'm looking for a dew heater/controller. I would preferably like more than one channel. Let me know what you've got and how much you want. It's to fit a 8" Newtonian, 2 x 50mm finderscopes so may just need to buy some more strips or make up one. Curious what people have for sale. Not looking to break the bank but would like it to run off of a 12v car/adapter plug. Can pay via paypal and need it before next friday.
  16. Just wondering how a typical mains powered 12v converter fares under heavy dew conditions, if it dews up inside it might blow itself and pop a mains fuse (hopefully the portable RCD first though). Shouldn't be any risk of electrical shock, but if the entire casing is dripping with dew then who knows? I have an old blue Halfords unit that has a power selector switch and a single power socket on the front. There's a car fuse on there too. It can chuck out a fair old amount of amps at 12v, which is the scary part for me. Should such a unit be wrapped up in a thermal blanket to delay the onset of dew?
  17. Hi All, I'm considering the purchase of a Panasonic toughbook (Amazon reseller refurb unit) to use outdoors to control my mount, skyris camera etc. I was planning to use my vaio but am a little concerned whether I could have problems with dew / damp weather. What do others use, does the heat from a laptop resolve the dew issue, any thoughts on the toughbook - advice / guidance / warnings appreciated. Regards, Tony
  18. Just had quite a frustrating night trying to image Orion's Nebula. I got my reflector polar aligned and out nice and early to acclimatise. Sadly I didn't get very far, even at high exposure times I got no hints of the nebula. I brought my scope in and found that all the optics were covered in condensation, which I'm assuming is what's caused the problem. It's a cold, clear night in Hull, I'd say seeing was fairly good, perhaps minimally misty. I've done a bit of Googling and searching on this forum and found stuff on dew shields and heaters. I was wondering if people had any comments or advice on how to deal with condensation? Thanks guys!
  19. I visited the International Astronomy Show in Warwick the other week. Just inside the door there was a young chap selling dew control products. The gear was lightweight and relatively inexpensive, so I thought I'd give it a try. I picked up one heater band (for my Esprit 120) and one 4 channel controller. The controllers he had at the show all had a 2m power cable. I said I would have preferred another metre. Tim (the young chap) said it was not a problem. He would make one with a 3m cable and send it out to me. He obviously posted it first thing Monday morning because it arrived on the Tuesday. What I liked about the unit was how lightweight it was. It also had a belt-loop sort of thing attached to the back. This allowed the elasticated part of the heater tape to pass through, so that the controller could be fixed to the scope itself. Here is how I have done mine: The controller works off one button (the small red button just under the printed text 'Quad Channel Dew Controller' on the case). When you power up, Output 1 is illuminated. Press and release (less than 1 second) to cycle between 0, 20, 40, 60, 80 and 100 percent output. There are 4 lights: 0% power = no lights, then each light comes on singly for 20, 40, 60 and 80 percent. All four lights are illuminated at 100% power. To switch channels, hold the button down for a bit longer (more than a second) and release. It is remarkably simple to use. With my other dew controller there seems to be a bit of 'uncertainty' as to whether or not the phono plug is properly seated. With the Dewcontrol unit the seating is extremely positive. One possible downside (or upside depending on your point of view) is that, when you power down, the unit does not 'remember' your settings. You start from zero power in each channel at each power up. This has caught me out once, unfortunately, but I will soon get used to the new way of doing things. I am very pleased with the unit. It is lightweight, inexpensive and works well. It is good to have a range of alternatives and this one is from a UK manufacturer. The heater tape worked just fine too. It was made by the lady who co-worked the stall with Tim (her name was Barbara). It seemed to be high quality. It is hand sewn. It worked straight away (unlike a top-end brand I bought a couple of years back that I had to pick apart and fiddle with). I am not sure if these are the same tapes that Tim sells on his website. My wife recalls that the brand of heater tape was W&W Astro - and Barbara's website is here http://www.dewheater.com/. I have no connection with Tim whatsoever. When looking up some info (his name for example) for this review, I found that his website was a little difficult to locate - if you are interested it is http://www.dewcontrol.com/. I may get one of his two channel units for my more portable setup. Steve M
  20. Wrote this one up as well: Simple QuikFinder Dewshield
  21. Yesterday had a gap in the clouds, quite unexpectedly. As clouds were supposed to close the gap by 10 pm, I used this occasion to test my new Raspberry Pi configuration (ubuntu mate, indi, phd). While sitting comfortably in my room, I controlled the rig from both PixInsight and Ekos/Kstars. Only polar drift alignment required outdoor action. The gap didn't close untill well after midnight, when temperature had dropped to the low noise numbers. (-11 C, according to my guide camera). This is what I met when ready to take my gear indoors. The diy dew shield/heater worked very well, no frost on the lens, the secondary mirror or the coma corrector. (The dew shield is black, not gray.) Also nice to have verified that the mount works great outside its specified temperature range. The dslr is weather proofed, and survived flawlessly. But I did need thick gloves when carrying all that metal inside. And seeing was too poor for any decent imaging.
  22. I am seriously thinking of buying the new Atik 414EXM. The high QE and relatively lower price is very attractive for narrowband. Sure I'd like a bigger sensor, but my budget won't let me. I used to have a QHY8, because the dew point here in Singapore is 1-2 degrees below ambient, I had to seal the camera inside a large bag filled with silica gel. By doing this scrupulously, I could eliminate frost on the sensor. My current camera is an ST8300M (the non-STF). This camera suffers from a very poor design in that it does not have a dessicant plug like the previous ST2000 and later STF8300 have. Hence after I started seeing frost/moisture on the sensor, I have to dis-assemble the camera and put in new dessicant. And not any dessicant will do, it has to be molecular sieve (I had to buy two cans from Sigma Aldrich). My question is around moisture control. How do these Atik bodies handle it?
  23. I have just ordered a 150P from FLO and pending its arrival I am reading up a bit on them, it seems that some people have noticed an improvement in contrast by flocking the inside of the tube, and also that fitting a dew shield is recommended. I can acquire a suitable dew shield, no problem there, but I have a question or several regarding flocking. What would I need to do in order to flock the inside of the tube? Do I need to remove the secondary mirror or anything else, and would I need to just cover the entire tube inside so that no original paintwork is showing? How difficult is it? Should I apply in sections, and if so does it matter how large or what shape the sections are so long as they are edge to edge? How many rolls of the flocking sheet that FLO sell would I need for the 150P? Should I flock the outside too? (I saw a post where someone wrapped what looked like pipe insulating foam around the entire OTA) Thank you for any advice!
  24. I intend to make one out of thin foam sheet (as available from The Works or similar stationary type shop), just wondering how long it should be. It should just slot over the end, perhaps be held in place by the dew heater tape or a piece of elastic.
  25. Hello everyone, second big night out with the scope and wasnt a bad one at that. The moon was at 98% full so bright as a spotlight on my now "claimed" dark sky spot out in the sticks around fife. Didnt see anything but the brightest stars but Jupitar, Mars and Saturn were still there shining bright as always to much enjoyment. The moon however was spectacular. I found that the moon filter was taking alot of the detail away and hiding alot in shadows so opted to use a 90° angle mirror and a barlow coupled with a 20mm lens to give a duller picture and it was fantastic! Got a quick pic on my phone looking through the lens. Dew wasnt a problem this time thanks to my new astrozap heat strip. Works very well - too well actually. Anyone have any hints on how to get the optimum temp on it as i was fiddling around with it abd no matter where i had the adjuster set i keep getting whats looks like thermal currents within the scope/dew shield distorting the picture occasionally. Any help negating this would be good but although it did stave off the dew completely. Also on that note my main optic on the front of my refractor is very dirty from the last dew build up ... how do i go about cleaning it cause ive heard mixed opinions on cleaning the main apeture.
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